The present disclosure relates to processes for increasing the chemical resistance or other properties of the surface of molded or formed products. Generally, a photoactive additive is included in the composition from which the product is molded. The surface of the product is then exposed to an effective dosage of ultraviolet radiation within a selected range of wavelengths. This causes crosslinking of the surface, especially when a polymeric base resin is included in the composition from which the product is molded.
Polycarbonates (PC) are synthetic engineering thermoplastic resins with desirable properties such as high impact strength and toughness, heat resistance, weather and ozone resistance, and good ductility. Polycarbonate polymers/resins and blends containing polycarbonate polymers also exhibit flame retardance properties. However, such polymers drip when exposed to a flame, and this behavior worsens as the wall thickness decreases. This behavior greatly diminishes their use in transparent and opaque thin wall applications where a V0 or 5 VA flame retardance rating is required. These polymers also have relatively poor chemical resistance. It would be desirable to provide additives that can improve these properties.